1. Field of the Invention
The present invention relates to a driving machine.
2. Description of the Related Art
Conventionally, a driving machine is known in which a fastener such as a nail is struck by a driver blade to drive the nail into lumber or the like. In this driving machine, the diver blade is driven by using compressed air, a fuel such as a gas, a motor, or the like as its power. In this driving machine, a fastener is supplied into an injection passage in which the driver blade slides, and the fastener in this injection passage is struck by the driver blade to drive out the fastener from an injection hole at a leading end of the injection passage.
In the driving machine which is adapted to drive out the nail in the injection hole by this driver blade, counteraction in the operation of the driver blade is produced in a main body portion of the driving machine, so that a phenomenon occurs in which the driving machine is operated in an opposite direction to the driving direction of the fastener. Due to this counteraction, torque in which a leading end portion of a nose portion forming the injection hole is moved forward is produced at the same time as the fastener is driven out from the injection hole. The nail in the injection passage can tilt due to this torque, in which case the nail is disadvantageously driven in this tilted state, resulting in faulty nailing finish. Particularly in the case of a nail having a small head diameter and a short shank length, since the angle of inclination of the nail in the injection hole becomes large, the tendency of the nail being driven in the tilted state becomes large.
To prevent this, as shown in JP-2004-330372-A, a structure is disclosed in which a guide member having an inside diameter conforming to the size of the fastener used is attached to a leading end of the nose portion, and the guide member is replaced depending on an application. In addition, as shown in JP-2004-330366-A, a structure is disclosed in which a rotatable guide member having an inclined surface defined thereon for guiding the leading end portion of the fastener to the center of the injection hole is disposed at a portion where the nose portion injection hole is formed.
With the structure in accordance with JP-2004-330372-A, the fastener can be suitably held so as to be capable of being driven in, and yet there have been problems in that the guide member is removed during the operation, and that the removed guide member can be lost. With the structure in accordance with JP-2004-330366-A, since the guide member is located on the sliding path of the driver blade, each time the fastener is driven in, the guide member is subjected to an impact force by the driver blade, so that it has been difficult to ensure the durability of the guide member.